Behe: Like tusks to elephants, the proteins are presumably useful to the parasite, other things being equal. But when the environment changes and the proteins become a net drawback, the quickest evolutionary solution is to get rid of them. That’s an interesting fact of biology and can be medically important. However, it’s important to note that it’s just one more example of devolution — the beneficial loss of genetic information.
The previous “earliest” record was from a fossil dated to 15 to 20 million years ago but what we don’t yet know is, did the mosquito then have the relationship it now has with the malaria parasite plasmodium? It’s a complex relationship, apparently. That could shed light on theories around evolution and strategies around malaria.